1. Field of the Invention
This invention relates to a television signal converter which can easily convert a television signal in MUSE system into a television signal, which can be produced by a television receiver in a present system.
2. Description of the Related Art
With advance of digital ICs, particularly the high speed of the memory, a large capacity of memories, and the low cost of manufacture, digital processing circuits for image signals have come into wide use. In addition, it has allowed for wider television screens, as well as higher definition.
On the other hand, a high-definition television system (MUSE system), which is completely different from the signals in the present system, has been developed. The MUSE system is disclosed in INTERNATIONAL BROADCASTING SYMPOSIUM ON RADIO AND TELEVISION ENGINEERING 1985 SESSION 2-(7) "Transmission of HDTV by MUSE system" by Yuichi Ninomiya et al.
In this system, since the signal band of this system is five times greater than that of the conventional television signal, the band-compression of the signal is performed in order that the signal transmission can be performed in the signal band corresponding to one channel of a broadcasting satellite. In this system, the band compression is performed by offset sampling the high-definition television signal between the fields and between the frames.
Therefore, since the television signal in the MUSE system is completely different from the signal in the present system, the image in the MUSE system cannot be output by the existing television receiver. Moreover, in order to receive the signal in the MUSE system and output the signal, a MUSE decoder, which has a large capacity of memories such as a frame memory, is required. As a result, in order to receive the signal in the MUSE system, a common user must purchase a MUSE decoder, which is completely different from the ordinary system, and is also more expensive. Therefore, the common user must bear a large expenditure of money.
Thus, the MUSE decoder, which can easily convert the signals in the MUSE television system into the signals in the present system, has been required.